As robotic work tool are becoming more and more advanced the requirements on their sealing is also increased which makes their bodies or chassis more (torsionally) rigid. This leads to that as the robotic work tool(s) runs over obstacles or holes causing one wheel to be lifted up by the obstacle, another wheel will also be lifted which may cause the robotic work tool to lose traction. Furthermore, any odometri may be affected by such slip and a proper navigation, such as by deduced (dead) reckoning, may be impeded.
Many prior art solutions are available that allow one wheel to move independently of the other, such as independent suspension, however, they suffer from being expensive and difficult to manufacture and to assemble—especially if they are to be able to detect collisions and/or lift events.
There is thus a need for a robotic work tool that is able to maintain traction even when operating in rugged terrain with many obstacles, but is still simple and cheap to manufacture and providing a reliable operation in rugged terrain.